Flow regulating valve



INVEN TOR.

DUNCAN B. GARDINER ATTORNEY Patented July 19, 1949 UNITED STATES 'PATENTorrlcs FLOW REGULATING VALVE tion of Michigan Application June 18,

v 17 Claims. l This invention relates to power transmissions,particularly to those of the type comprising two or more fluid pressureenergy translating devices, one of which may function as a pump-andanother as a fluid motor. y

In particular, the invention relates to an improvement in aflow-regulating valve comprising an adjustable throttle and acompensating valve for maintaining a constant flow across the throttlethrough which fluid is adapted to i'iow at a regulated rate regardlessof load resistance.

Flow-regulating valves have an important usein hydraulic powertransmissions for drivingmachine tools. They. serve the purpose oiproducing a reduced speed rate of the machine tool, and the machine toolmay be driven at a constant regulated rate of speed regardless ci loadresistance. l

In the past some diiiiculty was presented in preventing motor jump whenthe motor was started after interruption and in particular when amachine tool slide was moved into a feed position from rest or wherethere was a resumption of a feed movement after interruption during aslide movement. In many cases, if a feed movement was interrupted andthe operator-.of the machine tool did not back the tool away from thework before resuming a cut, the tool was ruined. This is due to the factthat, when iiow through the now-regulating valve is interrupted, thecompensating valve is held to the fully open position by a compensatingvalve spring. When flow is resumed after interruption, a temporary flowof iiuid above the normal regulated rate passes through the fully opencompensating valve before it is able to assume normal regulatingposition. Although this is only a momentary lapse and the compensatingvalve almost immediately y assumes normal regulating position, thistem-. porary flow of iluid above the normal regulated rate causes themotor to lump slightly before a constant regulated movement begins andruins a cutting tool.

In the past this diiiiculty has been avoided by the addition of valvesincorporated in the transmission to induce a ilow through theflow-regulating valve when flow to the motor was'interrupted, therebyplacing the compensating valve already in a position to regulatenormally when ow to the motor was resumed. This necessitated additionalvalves, lines and iittings in the hydraulic transmission.

It is an object of this invention to provide an improved now-regulatingvalve for use in a hy- 1945, Serial No. 600,601

' draulic transmission containing a fluid pump and motor which willprevent motor jump when iiow is resumed through the now-regulating valveafter interruption.

It is also an object of this invention to provide a flow-regulatingvalve which will prevent motor jump'when ow is resumed through thenow-regulating valve after interruption by preventing a ow above thenormal regulated rate before the compensating valve assumes regulatingposition.

It is also an object of this invention to incorporate in combinationwith an adjustable throttle and compensating valve, comprising aflow-regulating valve, a blocking valve to gradually permit a flow oiuuid up to the normal regulated rate when the motor is started afterinterruption and until thecompensating valve assumes now-regulatingposition.

It is a further object of this invention to provide an improvednow-regulating valve which will prevent motor Jump when now isresumedthrough the flow-regulating valve after interruption which may beeconomically manufactured, simple in operation, and which avoids theaddition to the hydraulic transmission of extra valves, lines or ttings.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing wherein a preferred form oi the present invention is clearlyshown.

In the drawing:

Figure l is a diagrammatic view of a hydraulic power transmission systemincorporating a preferred form of the present invention in the closedposition. v z

Figure 2 is a diagrammatic view of the same hydraulic power transmissionsystem shown in Figure 1 incorporating a preferred form of the presentinvention in a partially opened position.

Referring now to Figure 1, there is shown a pump I0, which may be drivenby an electric motor, not shown, which is supplied with fluid from atank l2 by means of a suction conduit i4 and which has a pump deliveryconduit il connected to the pressure port I8 of a suitablefour-waydirectional valve 20. A motor 22 having a piston 2i and a'plston rod 26is connected to cylinder ports 28 and 30 oi' valve 2li by means of aconduit 32 connected to the rod end and a conduit 3l connected to thehead end of said motor. A tank-port 38 of valve 2li is connected bymeans of a conduit 38 to an inlet port l0 of a flow-regulating valve l2.Valve 42 also has an 8 outlet port 44 which is connected to tank I2 bymeans of a conduit 48.

A suitable relief valve 48 may be provided in the pump delivery conduitI8 and is preferably constructed in accordance with the disclosure ofthe patent to Harry li` Vickers, No. 2,043,453. Valves of this charactermay be provided with a venting port for venting the control chamber inorder to permit the main valve to act as an unloading valve and bypassthe pump delivery at negligible pressure. A suitable,manually-controlled, two-way control valve is connected by means oi' aconduit 53 to a venting port 55 of valve 48 and to tank I2 by means of aconduit 51. In one position, valve 5| will close venting port 55 andpermit iiuid from pump I0 to enter valve 20 which directs it to motor 22to start said motor, while in anotherl position valve 5I will openventing port 55 to tank I2 by means of conduits 53 and 51, permittingvalve 48 to open completely and unload pump I0 to tank I2 by means of anexhaust conduit 59, thus stopping motor 22. Relief valve 48 also servesas a safety factor in limiting the maximum pressure attainable in thesystem, and cooperates with flowregulating valve 42 in exhausting totank I2 any amount of fluid from pump I0 in excess of whichflow-regulating valve 42 is adjusted to pass.

Flow-regulating valve 42 is comprised of a body 43 in which is containeda compensating valve 52, an adjustable throttle 54 and a blocking valve56. Compensating valve 52 is comprised of a hollow piston 58 connectedto which is a stem 59 provided With lands 60 and 8|. Piston 58 isshiftable within a longitudinal stepped bore 62 extending completelyacross body 43, and stem 59 is shiftable within a longitudinal bore 58extending the full length of a sleeve 64 which is tightly inserted inbore 82. A hollow plug threaded into the right end ofbore 62 forms achamber 55 in bore 52 between sleeve 64 and plug 55 and also limitsrightward movement of compensating valve 52. A spring 51 ofpredetermined resistance is 1ocated in a spring chamber 58 formed inbore 52 between piston 58 and a hollow plug 69 which is threaded intothe left end of bore 52. A chamber 10 is formed in bore 62 between theleft end of sleeve 54 and the right side of piston 58.

Inlet port 40 is in communication with an inlet chamber 1| formed inbore 53 of sleeve 54 between lands and 5| by means of an inlet passage12. Inlet chamber 1| is in communication with the throttle 54 by meansof a passage 14 and a groove 16 in sleeve 54 and a passage 18. Alongitudinal drilled passageway extending the full length of sleeve 54and which intersects passage 14 forms a means of communication betweeninlet chamber 1| and chambers 55 and 10. A passage 82 connectingthrottle 54 with blocking valve 56 has a'branch passage 84 incommunication 60 with spring chamber 58. Adjustable throttle 54 isrotatably mounted in a bore 85 which intersects passages 18 and 82 andserves as an adjustable restriction to iiow from passage 18 to pas- 85formed in the hollow portion of piston 06. A plate bolted to valve 42encloses piston 86 completely within bore 92 and passage 82. Spring 94normally positions piston 86 in bore 92 and passage 82 so that shoulder90 of piston 88 abuts a shoulder 81 of bore 92 and so that an outletpassage |04 in communication with outlet port 44 is blocked fromcommunication with passage 18. The inlet and outlet ports 40 and 44 arepreferably located at the back of the body 43 and arranged i'orconnection to the circuit lines by suitable panel mounting connectionssuch, for example, as are described in the Martin Patent No. 2,204,507.Piston 86 has a triangular slot 9B at the extreme right end of itsprojecting portion 88 and also has a restricted passage |00 whichconnects spring chamber 95 of-piston 85 with a chamber |02 of bore 92.

Referring now to Figure 1, in operation with the electric motoroperating pump l0 and with control valve 5| in the open position so asto direct full pump flow from conduit I5 to tank I2 and with motor 22stopped, compensating valve 52 will be in the open position shown. Whenfluid flow is thus directed from pump I0 to tank I2 to stop motor 22,uid flow ceases through flow-regulating valve 42, and spring 61 willshift piston 58 and stem 59 to the right.

When control valve 5| is shifted to close venting port 55 in order tostart motor 22, and with directional valve 20 shifted so as to connectconduit I6 with conduit a4 and conduit 32 with conduct 38 so as todirect Pump delivery to the head end of motor 22, fluid will bedelivered by pump I0 through conduit I5, ports I8 and 30 oi valve 20 andconduit 34 to the head end of motor 22. Discharging fluid from the rodend 4oi? motor 22 may enter conduit 32, ports 28 and 35 of valve 22 andby means of conduit 38flow to the inlet port 40 of valve 42. Due to thefact that compensating valve 52 is in the open position, land 50 permitsiiuld to enter from inlet passage 12, in communication with inlet port'40, to inlet chamber 1| and from there by means of passage 14, groove15, passage 18, throttle 54 and passage 82 to blocking valve 50, atwhich point a pressure increase occurs because piston 85 is blocking thedischarged fluid from motor 22 through outlet passage |04.

When there is a sufiicient pressure increase in passage 82, which isalmost instantaneous, the resistance of spring 94 is overcome, andpiston 86 will begin to shift to the left. Due to the fact that the apexportion of triangular slot 98 breaks over outlet passage |04 ilrst, onlya small amount of fluid is discharged through outlet passage |04, outletport 44 and conduit 45 to tank I2. In addition, a dashpot action will beprovided by restricted passage |00 in piston 86 which permits only asmall amount of fluid to leave spring chamber 55 of valve 55. .As theoperation of compensating valve 52 depends upon a, pressure drop acrossthrottle 54 equivalent to the pressure setting of spring 51,compensating valve 52 will not sage 82. Spring 51 normally biasescompensating 65 begin to close. As fluid iiow continues, piston 85 valve52 to the open position so that land 50 permits communication betweeninlet passage 12 'and inlet chamber 1|.

Blocking valve 55 is comprised of a hollow piswill continue to shift tothe left to permit a gradually increasing flow of fluid to dischargethrough outlet passage |04.

As is shown in Figure 2, piston 86, by a conton s6 having a, projectingportion as which forms 7o tinued but slow shifting to the left becauseof the a shoulder 90. Piston 85 is shiftable within a stepped bore 92which is in communication with passage 82, and its projecting portion 88is shiftable within passage 82. A spring 94 of predeterdashpot reactionprovided by restricted passage |00, has partially opened outlet passagevI 04. Compensating valve 52 is still in the open position because theflow is so small that the pressure drop mined resistance is located in aspring chamber 75 across throttle 54 up to this point has notexceedamargo ed the resistance of spring 41. However. as the ilo'wincreases, the pressure drop through throttie I4 increases, and the netforce acting on opposite sides oi piston 58 approaches the value of theforce of spring Il.

At this point. shown in Figure 2, a continued movement of piston 86 tothe left will create an opening in outlet passage III4 equivalent to theopening in throttle 54 which will -create a pressureA drop acrossthrottle 54 equivalent to the resistance of spring 6l, and iluidpressure in chamber 'I0 will start to shift piston 5l to the left whichwill create a smaller inlet for iluid in inlet passage l2. By the timepiston 8B has completely opened outlet passage |04, compensating valve52 has partially closed and is in a position to assume its normalregulating function.

The purpose of compensating valve 52, which is well known in the priorart, isto maintain a constant iiow across throttle 54, and itaccomplishes this by maintaining a constant pressure in inlet chamberil. Compensating valve 52 is responsive to the pressure drop acrossthrottle S, and. when the pressure. drop across throttle 5t slightlyexceeds the resistance oiered by spring El, compensating valve 52 willshift to the left to partially close inlet passage l2 to inlet chamberIl so as to allow just enough iluid inilow to maintain the pressure ininlet chamber 'II at a constant increment above that in passage 82.Pressure uid entering inlet chamber Il also enters chamber 'lll by meansof passage 'it and passage 80 where it acts against the right side ofpiston 58 and by passage 3G to chamber 6G where it acts against landtil. Fluid pressure crossing throttle 56 into passage t2 also enterschamber 68 by` means of passage @t where it acts against the left sideof piston 58. .An increase of pressure in inlet chamber li suilcient toovercome the resistance of spring 67- will cause compensating valve 52to shift to the left so that land 60 will tend to close-passage 'I2 toinlet chamber 1I to allow just enough fluid to enter inlet chamber 7i tomaintain constant the pressure drop across throttle 5d. The ilow acrossthrottle 5d will be uniformly constant so that piston 2d of motor 22will move at a uniformly constant rate of speed.

Throttle t is originally adjusted to pass a certain flow of iluid, theamount of which. naturally` will be less than pump capacity. The excessamount of fluid from pump I Il over the ow through valve i2 is exhaustedto tank I2 by means of relief valve d8.

If it were not for blocking valve 58, when motor 22 was started, thedischarged fluid from motor 22 would have a free outlet through thefully open compensating valve52 to tank I2 until compensating valve 52could assume the iiowregulating position. An ,amount of iiuid more thanthe normal regulated rate that compensatim,r valve 52 would ordinarilyallow to pass would be discharged to tank during this lapse, and piston24 of motor 22 would moveA much faster for a short distance than isallowable. Blocking valve 56. by permitting a gradually increasing flowof iiuid through outlet passage I 04 to tank I2, but

always below the amount -that compensating valve 52 would allow to passprovided it was in flow-regulating position when the motor was started,thus prevents a ilow of iluld above the normal regulated rate andthereby prevents motor jump when flow is resumed through ow regulatingvalve 42 after interruption.

If motor 22 is stopped and then restarted in the 6. other direction bymeans oi.' shifting valve 24 to connect conduit I6 to conduit l2 andconduit $4 to conduit 38, blocking valve I8 will perform the samefunction in the same way, as discharged iuid from the piston end oimotor 22 must pass through flow-regulating valve 42.

- It should be noted that, if at any time ow through the flow-regulatingvalve 42 should completely cease, in spite of the compensating valve 52moving' to the fully open position by the action of spring 61, blockingvalve 56 will shift to the closed position by reasonof spring 94. Thus,when ilow through the now-regulating valve 42 is resumed. a temporaryflow of fluid through the open compensating valve 52 above the normalregulated rate is prevented.

It should also be noted that blocking valve 58 permits a graduallyincreasing ilow of fluid, but never more than the normal regulated rate,when flow is resumed after interruption through ilowregulating valve t2.Triangular opening oi piston 86 first breaks over outlet passage E04,and, as piston 86 continues to shift to the left, outlet passage IMslowly and gradually opens because of the dashpot action provided byrestricted passage Illll in piston 86. Before piston t6 has shiftedcompletely. piston 58 of valve 52 acted upon by pressure in chamber I0will have started to shift which moves land 60 over inlet passage l2 atwhich time compensating valve 52 is in a position to assume its normalregulating operation.

Comnensating valve 52, when in a normal regulating position. is neverfully open or fully closed. Once compensating valve 52 assumesnormalregulating position when flow is resumed after interruption, blockingvalve 5S does not in any way interfere with the normal operation ofcompensating valve 52 and throttle 5d.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form. it is to be understood that other formsmight be adopted. all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. A :dow-regulating valve for controlling ow in hydraulic powertransmission systems comprising in combination, an adjustable throttlethrough which iluid is adapted to iiow at a normal regulated rate, apressure compensating valve responsive to the pressure drop across thethrottle for. maintaining the normal regulated rate and being of thetype which is normally open when ilow through the now-regulating valveis interrupted, and means preventing a, ow of fluid through thenow-regulating valve above the normal regulated rate when ow is resumedafterinterruption.

2. A flow-regulating valve for controlling ow in hydraulic powertransmission systems comprising in combination, an adjustable throttlethrough which fluid is adapted to iioW at a normal regulated rate, apressure compensating valve responsive to the pressure drop across thethrottle for maintaining the normal regulated rate and being of the typewhich is normally open when ow through the flow-regulating valve isinterrupted, and means responsive to pressure increases when iiow isresumed after interruption for gradually permitting the vnormalregulated rate of ow of uid through the now-regulating valve andpreventing ilow above the normal regulated rate. y

3. A flow-regulating valve for controlling ow in hydraulic powertransmission systems comprising in combination, an adjustable throttlethrough which duid is adapted to flow at a normal regulated rate, apressure compensating valve responsive to the pressure drop across thethrottle for maintaining the normal regulated rate and being of the typewhich is normally open when now through the now-regulating valve isinterrupted, and a resiliently-loaded 'blocking valve preventing a ilowof iiuid through the now-regulating valve above the normal regulatedrate when now is resumed after interruption.

4. A flow-regulating valve for controlling flow in hydraulic powertransmission systems comprising in combination, an adjustable throttlethrough which uid is adapted to flow at a normal regulated rate. apressure compensating valve responsive to the pressure drop across thethrottle for maintaining the normal regulated rate and being of the typewhich is normally open when flow through the now-regulating valve isinterrupted, and a resilientiy-loaded blocking valve responsive topressure increases when flow is resumed after interruption for graduallypermitting the normal regulated now oi iluid through the flow-regulatingvalve and preventing flow above the normal regulated rate.

5. A flow-regulating valve for controlling ow in hydraulic powertransmission systems having an inlet and an outlet and comprising incombination, an adjustable throttle through which fluid is adapted toilow at a normal regulated rate, a pressure compensating valveresponsive to the'pressure drop across the throttle for maintaining thenormal regulated rate and being of the type which is normally open whenflow through the now-regulating valve is interrupted,

.and a resiliently-loaded blocking valve beyond the compensating valveresponsive to pressure increases at the inlet when ow is resumed afterinterruption for gradually permitting the normal regulated flow of fluidthrough the now-regulating valve and preventing flow above the normalregulated rate.

6. A flow-regulating valve for controlling the ilow of fluid inhydraulic power transmission systems comprising in combination, apassage through which uid is adapted to flow at a normal regulated rate,and in series in said passage an adjustable throttle and a pressurecompensating valve responsive to the pressure drop across the throttlefor maintaining the normal regulated rate through the throttle and beingof the type which is normally open when flow through the passage isinterrupted, and means preventing a now of iluid through the passageabove the normal regulated flow rate when flow is resumed in the passageafter interruption.

'1. A flow-regulating valve for controlling the iiow of fluid inhydraulic power transmission systems comprising in combination, apassage through which iluid is adapted to ow at a regu- 60 lated rate,and in series in said passage an adjustable throttle and a pressurecompensating valve responsive to the pressure drop across the throttlefor maintaining the regulated rate and being of the type which isnormally open when ow through the passage is interrupted, and meansresponsive to pressure increases when now is resumed after interruptionfor gradually permitting the regulated now of nuid through the passageand preventing now above normal reguiatedrate.

8. A now-regulating valve for controlling the now of fluid in hydraulicpower transmission systems comprising in combination, a passage throughwhich fluid is adapted to flow at a regulated rate. and in series insaid passage an adinstable throttle and a pressure compensating valveresponsive to the pressure drop across the throttle for maintaining theregulated rate and being of the type which isnormaliy open when nowthrough the passage is interrupted, and a resiliently-loaded blockingvalve preventing a now of iluid through the passage above the regulatedrate when flow is resumed in the passage after interruption.

9. A now-regulating valve for controlling the ilow of fluid in hydraulicpower transmission systems comprising in combination. a passage throughwhich iiuid is adapted to iiow at a regulated .rate, and in series insaid passage an adjustable throttle and a pressure compensating valveresponsive to the pressure drop across the throttle for maintaining theregulated rate and being o! the type which is normally open when flowthrough the passage is interrupted, and a resiliently-loaded blockingvalve responsive to pressure increases when flow is resumed afterinterruption for gradually permitting the regulated iiow of uid throughthe passage and preventing flow above the regulated rate.

10. A flow-regulating valve for controlling the ow of fluid in hydraulicpower transmission systems comprising in combination, 'a passage havingan inlet and an outlet and through which` fluid is adapted to ow at aregulated rate, and

in series in said passage an adjustable throttle and a pressurecompensating valve responsive to the pressure drop across the throttlefor maintaining the regulated rate and being of the type which isnormally open when flow through the passage is interrupted, and aresiliently-loaded blocking valve beyond the compensating valveresponsive to pressure increases at the inlet when now is resumed afterinterruption for gradually permitting the regulated flow of uid throughthe passage and preventing ilow above the regulated rate.

11. In a hydraulic power transmission system containing a duid pump andmotor, a now regulating valve for controlling the speed of the motorcomprising in combination, an adjustable throttle through which nuid isadapted to now at a regulated rate, a pressure compensating valve 5oresponsive to the pressure drop across the throttle for maintaining theregulated rate and being of the type which is normally open when fluidflow through the now-regulating valve is interrupted, and meanspreventing a ilow of fluid 55 through the now-regulating valve above theregulated rate when now is resumed after interruption.

12. In a hydraulic power transmission system containing a iiuid pump andmotor, a flow-regulating valve for controlling the speed of the motorcomprising in combination, an adjustable throttle through which fluidisadapted to flow at a regulated rate, a pressure compensating valveresponsive to the pressure drop across the 55 throttle for maintainingthe regulated rate and being of the type which is normally open whenfluid new through the flow-reginating valve is interrupted, and meansresponsive to pressure increases when flow is resumed after interruptionfor gradually permitting the vregulated flow of nuid through thethrottle and preventing nowabove the regulated rate through saidthrottle.

13. In a hydraulic power transmission system containing a uid pump andmotor, a now-regulating valve for controlling the speed of the motorcomprising in combination, an adjustable throttle through which uid isadapted to ilow at a regulated rate, a pressure compensating valveresponsive to the pressure drop lacross the throttle for maintaining theregulated rate and being of the type which is normally open when fluidflow through the flow-regulating valve is interrupted, and aresiliently-loaded blocking valve preventing a ow of fluid through thedow-regulating valve above the regulated rate when ow is resumed afterinterruption.

14. In a hydraulic power transmission system containing a iluid pump andmotor, a flow-regulating valve for 4controlling the speed of theregulated rate.

15. In a hydraulic power transmission system containing a iiuid pump andmotor, a now-regulating valve for controlling the speed of the motorhaving an inlet and an outlet and comprising in combination, anadjustable throttle through which uid is adapted to iow at a regulatedrate, a pressure compensating valve responsive to the pressure dropacross the throttle for maintaining the regulated rate and being of thetype which is normally open when fluid ow through the flow-regulatingvalve is interrupted, and a resiliently-loaded blocking valve beyond thecompensating valve responsiveto pressure increases at the inlet whenflow is resumed after interruption for gradually permitting theregulated flow of iluid through the flow-regulating valve, therebyprecluding motor jump by preventing a flow of fluid abovethe regulatedrate when ow is resumed after interruption.

16. A self-contained now-regulating valve for controlling flow inhydraulic power circuits capable of gradually restarting ilow throughsaid valve after flow interruption therethrough comprising incombination, a unitary body having a single inlet and a single outletadapted to be connected in series in a circuit line.. an adjustablethrottle and a compensating valve in series between the inlet and theoutlet, the compensating valve assuming various regulating positions inresponse to the pressure drop across the throttle to maintain thepressure drop substantially constant and being normally biased to anon-regulating position while ow to the inlet is interrupted, and meansfor temporarily restricting ilow through the now-regulating valve whenflow is resumed after interruption until the compensating valve assumesa regulating position.

17. A self-contained now-regulating valve for controlling ow inhydraulic power circuits capable oi' gradually restarting ow throughsaid valve after flow interruption therethrough comprising a unitarybody having a dow-governing passage provided with an inlet and an outletand arranged to be connected in series in a circuit line, an adjustablethrottle and a compensating valve in series between the inlet and theoutlet, the compensating valve assuming various regulating positions inresponse to the pressure drop across the throttle to maintain thepressure drop substantially constant and being normally biased to anon-regulating position while ilow to the inlet is interrupted, andmeans for temporarily restricting flow through the iiow-regulating valvewhen ilow is resumed after interruption until the compensating valveassumes a regulating position.

DUNCAN B. GARDINER.

REFERENCES CITED The following referenlces are of record in the :die ofthis patent:

UNITED STATES PATENTS Number I Name Date 1,985,443 Clute Dec. 25, 19342,166,940 Conradson July 25, 1939 e FOREIGN PATENTS Number Country Date373,732 Great Britain June 2; 1932

